Improvement in wrenches



Patented July 12, 1870.

J, J. HULL.

Nut-Wrench.

ing is a specification.

W a single-threaded screw,

full strength of thc threads is preserved.

1 Figure 2, alougitudinal section .Figu'rc 3is the op ned-j m em tea

"JnMEsf-J. HULL, 0F BROOKLYN, NEW. XO'RKQ Letters Pitteat'No. 105,336, dated July 12,1870.

IMPROVEMENT m wnencnns.

v The Schedule referred to these Letters Patent and making part of the same t I, JAMES J L HULL, of the city of Brooklyn, county of Kings and State ot' Ne\vYork, have invented certain'lmprovementsin \l renches, otwhi'ch the follow.-

Nature and @bject. My invention relates toth'at-class of wrenches havjugadjustahle jaws of different degrces ol' strength a and opening; and r l 1 l a a The object of this invention is to seeurea quicker motion to the jaws in lnakingtheir adjustments without losing anythinginstrength.

Tl is is accomplished by the usc'oi' a double-threadc nut, one to the, right audfthe other tot-he left," and corresponding threads upon the bars thatcarry the jaws; consequent] y one-halfthe motion onlyeis required to open'or closetthe jaws that would be necessary in l Drawing. I

Figure 1 is a's'ule view of the wrench withtlie jaws elosed.' through both jaws. same view as fig. 1 butwith the jaws while,- at the same time, the

Aand B are the two bars that carry their jaws at their extremities. v y

O is the doublethreaded nut formed in two parts, and, when placed in or driven on and fastened in any convenient. manner;

At (If-are loops to assist in guiding-the jaws, iniad' (lit-ion to therib-in the center, as shown in the section,- fig. 2, but they also assist greatly in holding the jaws together inworking and relieving a spreading strain upon the nut.

In section, fig. 2, the two threads are plainly shown,

.and it is evident that one revolution of the nut will give twice the opening to the jaws that would be produced by a single-threaded nut of the same pitch of thread; but a singlethrczul'with twice the pitohwill nothave as much strength as this arrangement.

Hence, what I claim, is

An adjustable wrench, formed by the combination of the two bars A and B, double-threaded nut O, and

the purpose set forth.

hand E, 'as described, and for JAMES J. HULL.

Witnesses:

BojYD Elliott, SAM. G. HALL.

position, is fastenedtogether-by aband, E, which band may hecither screwed, shrunk, V 

